CONFIG_PPC is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

CONFIG_PPC (not configurable)

modulename: setup-bus.ko

configname: CONFIG_PPC

Linux Kernel Configuration
└─>PPC
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  
source code:
drivers/pci/setup-bus.c
selects
CONFIG_ARCH_MIGHT_HAVE_PC_PARPORT
CONFIG_ARCH_MIGHT_HAVE_PC_SERIO
CONFIG_BINFMT_ELF
CONFIG_OF
CONFIG_OF_EARLY_FLATTREE
CONFIG_HAVE_FTRACE_MCOUNT_RECORD
CONFIG_HAVE_DYNAMIC_FTRACE
CONFIG_HAVE_FUNCTION_TRACER
CONFIG_HAVE_FUNCTION_GRAPH_TRACER
CONFIG_SYSCTL_EXCEPTION_TRACE
CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB
CONFIG_VIRT_TO_BUS
CONFIG_HAVE_IDE
CONFIG_HAVE_IOREMAP_PROT
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
CONFIG_HAVE_KPROBES
CONFIG_HAVE_ARCH_KGDB
CONFIG_HAVE_KRETPROBES
CONFIG_HAVE_ARCH_TRACEHOOK
CONFIG_HAVE_MEMBLOCK
CONFIG_HAVE_MEMBLOCK_NODE_MAP
CONFIG_HAVE_DMA_ATTRS
CONFIG_HAVE_DMA_API_DEBUG
CONFIG_HAVE_OPROFILE
CONFIG_HAVE_DEBUG_KMEMLEAK
CONFIG_GENERIC_ATOMIC64
CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
CONFIG_HAVE_PERF_EVENTS
CONFIG_HAVE_REGS_AND_STACK_ACCESS_API
CONFIG_HAVE_HW_BREAKPOINT
CONFIG_ARCH_WANT_IPC_PARSE_VERSION
CONFIG_SPARSE_IRQ
CONFIG_IRQ_DOMAIN
CONFIG_GENERIC_IRQ_SHOW
CONFIG_GENERIC_IRQ_SHOW_LEVEL
CONFIG_IRQ_FORCED_THREADING
CONFIG_HAVE_RCU_TABLE_FREE
CONFIG_HAVE_SYSCALL_TRACEPOINTS
CONFIG_HAVE_BPF_JIT
CONFIG_HAVE_ARCH_JUMP_LABEL
CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
CONFIG_GENERIC_SMP_IDLE_THREAD
CONFIG_GENERIC_CMOS_UPDATE
CONFIG_GENERIC_TIME_VSYSCALL_OLD
CONFIG_GENERIC_CLOCKEVENTS
CONFIG_GENERIC_STRNCPY_FROM_USER
CONFIG_GENERIC_STRNLEN_USER
CONFIG_HAVE_MOD_ARCH_SPECIFIC
CONFIG_MODULES_USE_ELF_RELA
CONFIG_CLONE_BACKWARDS
CONFIG_ARCH_USE_BUILTIN_BSWAP
CONFIG_OLD_SIGSUSPEND
CONFIG_OLD_SIGACTION
CONFIG_HAVE_DEBUG_STACKOVERFLOW
CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
CONFIG_ARCH_USE_CMPXCHG_LOCKREF
CONFIG_ARCH_SUPPORTS_ATOMIC_RMW